Table II.

Humoral immunodeficiency disorders associated with recurrent infectious CRS⁴²

Diagnosis	Laboratory findings
Common variable immunodeficiency (CVID)	Low IgG and low IgA or IgM levels with lack of functional response to polysaccharide vaccines (poor T-cell-independent antibody response), normal or low B-cell numbers
Specific antibody deficiency (SAD)	Poor functional response to polysaccharide vaccines (poor T-cell-independent antibody response) with normal immunoglobulin levels, normal B-cell numbers
Selective IgA deficiency	Low IgA (<7 mg/dL) with normal IgG and IgM levels, normal B-cell numbers
IgG subclass deficiency	One or more low IgG subclasses with normal total IgG level, normal B-cell numbers

CRS, Chronic rhinosinusitis.